Provide record initialization syntax

tools/support.rb

@@ -15,7 +15,7 @@ class BuildTarget
   attr_accessor(:build, :gcc, :sysroot, :tmp)
 
   def initialize
-    @sysroot = '/'
+    @sysroot = Pathname.new '/'
   end
 
   def gxx
@@ -55,7 +55,7 @@ def find_build_target(gcc_version)
       end
     end
   result.tmp = TMP
-  result.sysroot = sdk
+  result.sysroot = sdk unless sdk.nil?
   result
 end